Abstract
Laurel wilt is a destructive vascular disease responsible for high mortality of American tree species in the family Lauraceae, particularly redbay (Persea borbonia) and swampbay (P. palustris), two dominant components of Coastal Plain forest communities in the southeastern United States. The disease syndrome emerged as a result of establishment of an exotic wood-boring beetle, Xyleborus glabratus, now known as the redbay ambrosia beetle. During gallery excavation, females of X. glabratus introduce a newly-described, obligatory fungal symbiont, Raffaelea lauricola. This fungus proliferates within the gallery and provides food for the beetles, but it has proven to be pathogenic to American lauraceous hosts, which have had no co-evolved history with R. lauricola. Presence of the foreign fungus elicits secretion of resins and formation of extensive parenchymal tyloses within xylem vessels. The extreme defensive response results in blockage of water transport, systemic wilt, and ultimately tree death. The beetle vector was first detected near Savannah, Georgia in 2002, and since has spread throughout the Southeast to become established in six states. The epidemic spread south through Florida more rapidly than predicted and currently threatens commercial production of avocado (Persea americana). Recent research indicates that California bay laurel (Umbellularia californica) can serve as a reproductive host for X. glabratus and is susceptible to laurel wilt disease. Thus, the US Pacific coastal forest ecosystems (and the California avocado industry) would be negatively impacted should the vector become established along the western coast. This review article summarizes our current understanding of the insect vector, the mycopathogen, and the susceptible host tree species. It also addresses elements of disease management and limitations with our current detection methods for redbay ambrosia beetle, which rely on manuka oil lures. Of the host-based attractants evaluated, cubeb oil shows the most promise as a potential new lure for X. glabratus.
Highlights
Laurel wilt is a lethal vascular disease of American tree species in the plant family Lauraceae
Another consequence of “diameter-preference” by the vector is that the oldest trees are typically the first to be attacked by X. glabratus and to succumb to laurel wilt disease (Figure 4(b))
Laurel wilt is firmly established within the southeastern United States, and its geographic range continues to expand
Summary
Laurel wilt is a lethal vascular disease of American tree species in the plant family Lauraceae. Since its introduction into the United States a decade ago, laurel wilt has spread extensively throughout the southeastern Coastal Plain, escalating to epidemic proportions. It has had severe impact on forest ecosystems, decimating large poputions of native Persea trees, notably redbay [P. borbonia (L.) Spreng.] and swampbay [P. palustris (Raf.) Sarg.] [1]. Ambrosia beetles (Curculionidae: Scolytinae and Platypodinae) are a diverse, polyphyletic group of wood-boring insects that feed on symbiotic fungi, which they cultivate in galleries within the interior (mostly dead) xylem layers of host trees [7]. Benign in its native lands [12], the redbay ambrosia beetle has acquired pest status upon entry into the US, where its symbiotic fungus is pathogenic when introduced into new (naïve) host trees
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
